Select three keywords from this text "While there are known records of structured exercise (weightlifting, aerobics and fitness training) being used in China, the Zhou dynasty (1046-256 BCE) and Ancient Egypt (2575-2130 BCE), it was the Ancient Greeks who truly set things in motion. They are cited as the creators of the gymnasium, a dedicated place for people to exercise and train.Gymnasium derives from the Ancient Greek world gymos, which means naked, and that’s previously how athletes would train and compete in these open-air venues. Showing off the athletic male form was not only for aesthetic reasons, but it’s also thought to have been a tribute to the gods. Note that only men were permitted to train, a stance that would be upheld by many civilisations to come."